CVE-2017-3226: Das U-Boot's AES-CBC encryption feature improperly handles an error condition and may allow attacks against the underlying cryptographic implementation and allow an attacker to decrypt the data

Vulnerability summary

CVE-2017-3226 is a medium (CVSS 6.4) vulnerability in das u-boot. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 17.5% of scored vulnerabilities.

Timeline

1. 24-07-2018
   PublishedVulnerability first disclosed.
2. 05-08-2024
   Last modifiedVulnerability information updated.

Description

Das U-Boot is a device bootloader that can read its configuration from an AES encrypted file. Devices that make use of Das U-Boot's AES-CBC encryption feature using environment encryption (i.e., setting the configuration parameter CONFIG_ENV_AES=y) read environment variables from disk as the encrypted disk image is processed. An attacker with physical access to the device can manipulate the encrypted environment data to include a crafted two-byte sequence which triggers an error in environment variable parsing. This error condition is improperly handled by Das U-Boot, resulting in an immediate process termination with a debugging message.

• CWE-329Generation of Predictable IV with CBC ModeThe product generates and uses a predictable initialization Vector (IV) with Cipher Block Chaining (CBC) Mode, which causes algorithms to be susceptible to dictionary attacks when they are encrypted under the same key.
• CWE-310Cryptographic IssuesWeaknesses in this category are related to the design and implementation of data confidentiality and integrity. Frequently these deal with the use of encoding techniques, encryption libraries, and hashing algorithms. The weaknesses in this category could lead to a degradation of the quality data if they are not addressed.